On 12/10/2016 8:06 AM, slate_leeper wrote:
I wrote a while back about an underground water leak. Well, I have
determined that the water leak is not in the feed line but is within
the structure. I was misled by a main shutoff valve that didn't fully
shut off.

So, back to the problem. I am using 120 gallons a day (5 gallons per
hour) in a house that is unoccupied. I have inspected everywhere.
There are no dripping faucets. All toilets have been shut off. There
is no visible moisture anywhere. This is a 70's "raised ranch" style
house with no crawl space. Once the water main enters from the street,
all piping is within the structure.

So where the heck is it leaking?

In my previous house, the water entered into the basement where there
was a meter and water heater. Hot and cold went upward to 3 bathrooms.
But, hot and cold also went under the concrete to the laundry area
(basement) and also above that, to the kitchen. In the kitchen you
could run the hot waiting for it to arrive, which didn't take too long.
However, if you then turned off the water and returned only a few
minutes later, the water was no longer hot. I discovered where the heat
was going when walking through the basement barefoot. I immediately ran
a new run (insulated) along the basement ceiling. Problem solved. So,
in you case, some pipes could even be under a basement floor and
possibly be leaking.